We’re chronicling 100 days of Indy 500 history on #SpeedRead leading up to the historic 100th Running. With 39 days to go, IMS Historian Donald Davidson explains another cherished Indy 500 tradition.
More Donald Davidson: The Yellow Shirts | Origins of: the “Greatest Spectacle in Racing” | “Back Home Again in Indiana” | Brick-kissing | The milk | The Pace Car | Why Indy is a 500-miler | Why it’s 33 cars | How “Gentlemen, Start Your Engines” began | More 100 days blogs
An aerial bomb has signaled the opening of the track on race morning every year since 1911. From the time the facility opened in 1909, up through 1947, all of the policing was conducted by the Indiana National Guard. For many years there was a series of bombs throughout the morning, starting with one-hour intervals and reducing to 15 minutes, 10 minutes and five minutes. The interval bombs were discontinued at some point in the 1950s, and the procedure for many years thereafter consisted of the gate-opening bomb followed several hours later by an alarmingly noisy cluster as the field of 33 cars negotiated the south end of the track on the first lap. This was discontinued sometime in the early 1990s, with the gate-opening bomb now being the only one that remains. In terms of efficiency and expense, it seems there could hardly be a more efficient and economical way of advising all stations around the circuit that it is time to open the gates than one straightforward bang!